Peroneus quartus muscle

Originally, several accessory muscles were distinguished in the peroneal compartment:

peroneus quartus (PQ) (Otto)

peroneus-calcaneus externum (Hecker)

peroneus accessorius (White)

peroneus digiti quinti (Testut)

This terminology has been simplified by summarising all peroneal compartment variants under the definition of a peroneus quartus muscle as a muscle arising from the lower leg and inserting onto the lateral hind and midfoot. This explains the variable insertion sites of the PQ muscle: